It is known in the art that systems using multiple antennas at the transmitter and one or more antennas at the receiver can achieve dramatically improved capacity, i.e., the maximum bits/second/hertz with error free communication, as compared to single transmitter antenna systems. It is also known in the art that if a channel estimate, or channel statistics based on the channel estimate, are fed back to the transmitter, then the throughput of the channel can be improved with respect to an identically configured system but without feedback. However, because in systems with multiple transmit antennas the overall channel is actually made up of multiple channels, with one channel for each transmit and receive antenna pairing, such feedback requires considerable bandwidth, and it is undesirable to dedicate so much bandwidth to feedback. Also, for fast changing wireless channels, the feedback may not arrive at a fast enough rate in order to be useful.
In order to achieve the maximum open loop capacity of a multiple transmit antenna system, it is necessary to employ channel coding. The state of the art of channel coding, e.g., turbo codes, trellis codes and the like, is typically spatially one dimensional, i.e., they are designed for only a single transmit antenna. Generally, it is not immediately obvious how one could employ such coding in a spatially multi-dimensional, e.g., multiple transmit antenna, system. In the case of two transmit antennas and one receive antenna, it was recognized that each of the data substreams could be independently coded using known channel coding techniques to achieve maximum capacity if so-called “space-time spreading” was used. See for example, U.S. patent application Ser. No. 09/285,578 entitled Space-Time Spreading Method Of CDMA Wireless Communication.